I'm more than ok with it.
Fastest Serie A player, best dribbler in the last two seasons, very good passing acc, young, 0 cash paid.
Marrone can play in his natural position regularly and get rid of PDC.
Maybe Conte is not sure about Pepe's health and want to make sure that he can switch to 433-424 anytime? Biabiany is younger/better than Pepe anyway.